Well bit construction



Feb. 8, 1938. A. c. CATLAND 2,107,627

' WELL. BIT CONSTRUCTION Filed'ocnl-s, 193e 'lll/1111 2 Sheets-Sheet 2 @www H5' @Zio/WS? Patented Feb. 8, 1938k APATENT OFFICE WELL arr ooNsTanc'noN v`aurea c. Garland, Alhambra, cani.

Application om 1s, 193s', sem No. 105,371 s claims. (ol. s55-71) This invention relates to well drilling toolsA and relates more particularly to an improved construction for roller rock bits. AV general ob- :lect of the invention is to provide an improved well bit construction that is extremely simplevand that is strong and long wearing. I

In Toller rock bits for use in the rotary method of well drilling it is very desirable to, provide for the transmission of the stresses and forces from the parts receiving the same directly to the body or shank of the tool. In bit structures where the d stresses are transmitted from one member to a second member and then from the second member to the shankconsiderable play and wear develops between the parts due to the essential tolerances in the machine work and poor workmanship.

Another object of this invention is to provide a strongpractical bit construction in which the parts that receive the severe operating stresses transmit such stresses directly to the body of the bit.

Another object of this invention is to provide a roller bit construction in which the cutter carrying shafts or pins have their opposite` end portions directly bearing on integral parts of the blt body for the direct transmission ofthe operating forces tothe body.

Another object of this invention is to provide a bitv construction of the character mentioned in which the inner cutters are partially rotatably supported on the pins and are partially rotatably supported directly on integral parts of the shank.

A further object of the invention is to provide a bit construction of the character mentioned that may be easily and quickly repaired or reconditioned when worn.

'I'he various objects and features of my invention will be fully understood from the following detailed description of a typical preferred form and application of the invention, throughout which description reference is made to the accompanying drawings, vin which:

Flg. l is a central longitudinal detailed sectional view of a bit embodying the present inventio. Fig. 2 is aside elevation of the bit with the lower portion appearing in vertical cross section in a plane normal to the plane of sectioning of Fig. l, and Fig. 3 is a fragmentary vertical detailed sectional view illustrating the manner in which the bitmay be reconditioned.

The bit illustrated in the drawings and embodying the present invention includes, generally, a shank or body I0, two sets of inner roller cutters I I and I2, means I2 for rotatably supporting the .20 are provided on the inner sides of the legs .structure illustrated in the drawings a tapered screw threaded socket I1 extends into the upper end of the body l0 to receive a threaded pin I 8 of a drill collar or similar part on the string S. 10 In accordance with the invention the body I0 is an integral member comprising an upper portion and depending parts or wings. The upper portionof the body I0 'maybe cylindrical, as illustrated. Two legs or wings I8 project downwardlo 1y from the lower end of the body I0 at diametrically opposite points. 'I'he particular body I Il illustrated has a downwardly and outwardly flared lower portion Ii and the legs I 0 project downwardly from the portion Ii. Fiat thrust surfaces 20 I9. 'I'he surfaces 20 are inclined downwardly and inwardly. 'I'he lower ends 2| of the wings I9 are flat and normal to the surfaces.

The integral body Il further includes legs or 25 wings 22 projecting downwardly and outwardly from the lower body portion It. The legs 22 are spaced substantially 90 from the wings I9.

, Raised thrust surfaces 22 are provided on the inner sides of the wings. 22. 'Ihe surfaces 23 are 30 inclined downwardly and outwardly with respect to the vertical axis of the bit. The lower ends 24 of the wings 22 are ilat and substantially normal to the surfaces 2l. The'fou'r spaced wings I9 and 22 denne an open socket-like space at the 35 lower end of the body III. An integral partition or wall 25 of the body Il separates this space from the lower end of the soci-:et l1. In accordance with the invention a stud or web 26 depends from the body wall 25. The web 2l is an integral 40 part of the body III and lies in or adjacent a central vertical plane of the body. 111e opposite side edges of the web 2l which oppose the wings 22 are provided with projecting wings 21. The wings 21 are integral with the web 2l and are inclined 45 downwardly and outwardly. Raised thrust surfaces 28 are provided on the outer sides oi' the wings 21. 'lhe surfaces 22 are substantially parallel with the thrust surfaces 23 of the wings 22. The lower ends 2l of the wings 21 are prefer- 50 ably ilat and normal to the surfaces 28.

In accordance with the invention the stud or web 2C is characterized by integral bearing parts 3l projecting from its opposite sides toward the wings II. The bearing parts are cylindrical vand their longitudinal axes are normal to the bearing surfaces of the wings I9. Bosses 3I are provided on the web at the bases or inner ends of the bearing parts 30. The outer ends of the bosses 3l form at annular thrust surfaces 32. The peripheries of the bosses 3I are prefer ably chamfered or bevelled, as illustrated. The outer-ends of the bearing parts are preferably flat and normal to the longitudinal axls of the parts. It will be noted thatthe bearing parts 30 and the bosses 3I are integral elements of the shank or body I0.

The cutters II are rotatably supported at the lower end of the body I0 to act on the inner portion of the well bore. The inner cutters are provided in sets or pairs each pair including a cutter II and a larger cutter I2. The cutters II and I2 are roller cutters, the cutters II being cylindrical and the cutters I2 being frusta-conical. The cylindrical cutters II have central 1ongitudinal openings 34 and peripheral cutting teeth 35. The cutting teeth 35 may be 'straight and axial as illustrated. In accordance with the invention the inner ends of the teeth 35 project beyond or overhang the inner ends of the cutters II. The opposite ends of the cutters II may be hat and normal to the axis of the cutters. The frusto-conical cutters I2 are provided with central longitudinal openings 35 and peripheral cutting teeth 33. 'I'he teeth 33 may be spiralled or may be straight and axial as illustrated. The opposite ends of the cutters I2 are preferably at and the teeth 33 may extend beyond or over'- hang the outer ends of the cutters. The cutters I2 are longer and somewhat larger in diameter than the cutters II. In practice the small ends of the ,frusto-conical cutters I2 may be larger in effective diameter than the cutters II.

The means I3 for rotatably supporting the inner cutters I I and I2 is a feature of the invention. The meansl I3 provides for the mounting of the cutters II and I2 on shafts or'pins 31 which are directly carried by integral portions-.of the body I0. In accordance with the invention a downwardly and outwardly inclined opening 38 is provided in the lower portion of each wing I Il and a correspondingly inclined socket 39 is provided in each bearing part 30. The sockets 39 may extend inwardly through the bosses 3| tot have their inner ends in communication. -The cutter supporting shafts or pins 31 are passed inwardly through the openings 38 and have their inner end portions threaded in the sockets 39. The threaded inner portions of the pins 31 may be reduced in diameter so that the pins present inwardly facing annular shoulders 40 which bear on suitable surfaces of the bearing parts 30. Heads 4I are provided on the outer ends of the pins 31 and dt suitable recesses or sockets 42 in the outer sides of the wings I9. The heads 4I may be socketed to facilitate the threading and unthreading of the pins 31. Edge portions 43 of the pin heads 4I may be peened over into notches 44'in the outer sides of the wings III to prevent unthreading of the pins 31.` When the pins 31 are properly threaded in place they serve to tie the wings I9 to the web 25, thus strengthening the bit assembly. The pins 31 pass through the longitudinal openings 34 of the cutters II and the longitudinal openings 35 of the cutters I2 to rotatably support the cutters. In accordance with the invention the inner portions of the cutters II flt around and rotatably bear on the bearing parts 30 while anti-friction rollers 45 or other suitable means clearance with the bosses 3I. The teeth 35 over--v hanging the bosses 3| project inwardly to immediately adjacent the center of the bit at thel lower end of the web 25 to act on the innermost portion of the well bore and to prevent contact of the web 25 with the earth formation. The inner ends of the` cutters II may bear on the thrust surfaces 32 of the bosses. 3|.

The frusto-conical inner cutters I2 are rotat- `ably supported on the pins 31 through rollers 45 or other equivalent anti-friction bearing means. Thrust washers 41 may be arranged in the inner ends of the cutters I2 to separate the vrollers 45 and 45 and to receive end thrusts from the cutters II. The cutters I2 are arranged with their small ends facing inwardly so that the cutters II and I2 act on a tapered mound on the bottom wall of the well bore. As the inner ends of the tapered cutters I2 are larger in diameter than the cutters II this mound on the bottom wall of the well bore is stepped so that the cutters on vthe mound are eiective in centralizing and stabilizing the bit. Non-rotatable thrust washers 48 are interposed between the outer ends of the cutters I2 and the thrust surfaces 20 of the wings I 9. Tongues *or lugs 49 project from the washers 48 and cooperate with the at ends 2I of the 1 wings I9 to holdthe washers against rotation.

The outer cutters I4 are frusto-conical roller cutters. 'Ihe cutters I4 are provided with central longitudinal openings 52 and may have at opposite ends as illustrated. Cutting teeth 53 are provided on the peripheries of the cutters I4. The teeth 53 may be straight or spiralled, as desired. The outer corners of the teeth 53 are preferably bevelled off while the inner ends of the teeth may slightly overhang the inner ends of the cutters.

The cutters I4 are rotatably vmounted between the wings 22 and 21 to act on the outer portion of the well bore-and to cut the bore to gauge. The means for rotatablyl support-ing the cutters I4 includes bushings 54 arranged longitudinally through the cutters I4.l The bushings 54A are positioned between the adjacent opposing wings 22 and 21 to have their longitudinal axes inclined downwardly and inwardly to be normal to the surfaces 23 land 25. Pins 53 carry the bushings 54. The pins 53 are passed outwardly through downwardlyland inwardly inclined openings 54 in the wings 21 and are threaded into correspondingly inclined openings 55 in the wings 22. The outer ends of the pins 53 may be peened into notches 55 in the wings 22 to prevent unthreading of the pins. Suitable rollers 55 or other antifriction bearing means may rotatably support the cutters I4 on the bushings 54. The cutters I are arranged with their large ends outermost and are rotatably supported on the inclined bushings 54 so that the bevelled oif outer ends of their teeth 53 are substantially vertical as they come into engagement with the earth formation. Thrust flanges 55 are provided on the inner ends of the bushings 54 to bear against the surfaces 28. The flanges 55 space the inner ends of the cutters I4 from the wings 21. Lugs 51 project from the flanges 55 and cooperate with the ends 29 of the wings 21 to hold the bushings 54 against rotation and to assist in transmitting upward thrusts to the wings. Thrust washers 58 are arranged on reduced outer end portions of the bushings 54 to space tlel cutters Il from the wings 22 and to transmit the end thrusts from.

the cutters to the wings. The washers 58 may be pressed or force-fitted on the bushings 54 to stantiallyilush with the outer surfacesvof the wings 22.

The invention provides means for flushing the `cutters Il and I2 and the cutters I4. Ports 88 s as illustrated in Fig. 3.

are provided in the body wall 25 to conduct the circulation fluid downwardly from the socket I1 to the spaces which house the pairs of cutters Il and I2. The circulation fluid is discharged downwardly from the ports 60 to impinge against the cutters I I and I2. Similar ports 6I are provided in the body wall 25 to communicate with the lower end of the socket I1. The ports 6I discharge the circulation fluid downwardly against the upper parts of the cutters I4.

In accordance with the invention the bit may i -be easily and inexpensively reconditioned when worn. In the event that the lower portion of the web 26 carrying the bearing parts 30 becomes worn it may be machined off to a flat surface 10 'I'his will, of course. remove the wings 21 as well as the bearing parts 30 and the bosses 3i. A replacement part or element 1I is then integrally joined with the body l0 to replace the portions machined oil'. 'I'he replacement element 1I has a flat upper end 12 to bear against the surface 10. The element 1| i's integrally joined with the'body I0 by welding 13. The replacement element 1I -is identical with the lower portion of the web 25 as originally constructed, that is, it has Wings identical with the wings 21 and has bearing parts 30 and bosses 3| identical with the above-'described bearing parts and bosses. When any other parts of the bit that may have been worn have been replaced or reconditioned the -bit provided with the re` placement element 1I may be reassembled and again operated.

.In operation the bit is connected with the' lower end of the rotary well drilling strings and is op.

erated in the well bore in the usual manner. The outer cutters I 4 act on the outer portion of the well bore to cut the bore to gauge and to make an annular cut at v the bottom of the bore. The inner cutters II and I2 act on the inner part of the well bore and form a mound of earth formation on the bottom wall of the bore. As described above, this moundhis stepped and the cutters II-and I2 acting on the stepped conical mound of earth formation materially assist in guiding and centralizing the bit. It will be observed that the several cutters Il, I2 and Il are v rotatably supported by shafts or pins 31 which are direct1y carried by the body I0. 'I'he inner cutters I2 and the outer portions of the cutters vII are rotatably supported by the pins 81 which have their opposite end parts directlycarried by integral elements of the body I0. -This mounting of the cutters-prevents the development of undesirable play and clearance between the bit parts. The cutters Il have their inner portions rotatably bearing on the integral bearing parts lintegral with the body. an integral to be limited or restricted to the specific details herein set forth, but wish to reserve to myself any variations or modifications that may appear to those skilled in the art or fall within the scope of the following claims.

Having described my invention, I claim:

1. In a roller bit, a body, a wing depending from the body, a web depending from the center of the body, the wing and web being integral with the body, an integral bearing part on theV web, the wing having an opening, the web having an opening concentric with the bearing part, a pin extending between the wing and web and having its end portions directly supported in said openings, a cutterrotatably supported on the outer portion of the pin, and a cutter whose inner portion rotatably bears on said bearing part and whose outer portion is rotatably supported by the pin.

2. In a roller bit, a body. a wing depending from the body, `a web depending from the body, the wing and web being integral with the body, an integral Ibearing part on the web, the wing and said bearing part having openings, a pin passed inwardly through the opening in the wing and threaded in the opening in the bearing part, a head on the pin cooperating with the wing, a cutter partially rotatably supported on the bearing part and partially rotatably supported on the pin, and a second cutter rotatably supported on the pin between the wing and the first mentioned cutter.

3. A roller bit including, a body having depending'wings at its periphery, a web depending from the center of the body between the wings, the

wings and web being integral with the body, pins projecting upwardly and inwardly from the wings, a single element integrally joined to the 4. A roller bit including, ai body. wings projecting from the lower end of the body. a web projecting downwardly between the wings, the

-Wings and web being integral with the bOdy,

parts on the web projecting toward the legs, the wings and web having Ainclined openings, the

openings in the web extending through saidparts, pins through' the openings in the wings and threaded in the openingsl in the web to be directly carried by the wings and web. heads'on the pins cooperating with the wings whereby the pins tie together the wings and web, and roller cutters rotatable on the pins and overhanging the said parts of the web in which the pins are carried.

5. In a roller bit, a body, a wing depending from the body and havingan opening, a web depending from the body, the wing and web on the web having a threaded opening, a

' extending between the wing and web and having its inner end directly threaded into the opening insaidbearingpartand having its outerend supportedintheopeninginthewmg,anda

cutter whose inner portion rotatably bears c-n said bearing part and whose outer portion is rotatably supported by the pin. A

6. In a roller bit, a body, wings depending from the body, a central web depending from the body, the wings and web being integral with the body, integral bearing parts on the web facing the wings, the wings and said bearing parts having openings, the openings in the bearing parts being threaded, pins passed upwardly and inwardly through the openings in the wings and threaded in the openings in the bearing parts,- and roller cutters "partially rotatably supported by the bearing parts and partially rotatably supported by the pins, the peripheries of the cutters below the web being in close proximity to protect the web.

ALFRED C. CATLAIu-D. 

